A man who police believe could be responsible for as many as 19 robberies in Monterey County since early March was arrested over the weekend.Omar Rios Morales, 30, a Soledad resident who used to live in Salinas, was booked into Monterey County jail in connection with 13 robberies and is being investigated as the prime suspect in six others, Salinas police said. The county district attorney’s office has not yet filed charges against Morales for six other robberies, but police detectives said they believe Morales is responsible for all 19 crimes. The robberies were carried out in Salinas between March 5 and the day of Morales’ arrest.